K20 Suburban Transmission Issue

[ch2000]

I recently purchased a decent shape Suburban K20 but I have run into a little issue that I was hoping you guys might be able to help me with. I have been away from Chevy 4x4s for sometime so I am not sure on this one.

I had to have the truck towed last week due to a little issue and after the truck was towed (Flatbed) the truck will roll while in park. The transfer case was put into neutral as it is still a full time 4x4 system by the tow truck driver and then loaded. Once it was dropped off to my house the transfer case was put back into 4-HI LOC but when I put the truck in park it will still roll. I tried putting the transfer case in different ranges but when I put it in park it will roll. I can drive it with no problem forward and reverse.

Any input would be appreciated, also the trans is a TH400.....

[Black_Duck]

Trans parking paw not engaging? Did it engage before?

[ch2000]

Originally Posted by Black_Duck

Trans parking paw not engaging? Did it engage before?

Engaged with no problems prior to the tow....

[Blue_71]

by flat bed you mean roll-back right? are both driveshafts still installed?

[ch2000]

Originally Posted by Blue_71

by flat bed you mean roll-back right? are both driveshafts still installed?

Yes a roll-back was used and the drive shafts are in place. What happen was I was driving normally and then all of the sudden I slung a belt. When I stopped the truck to take a look under the hood my harmonic balance had cam apart. So instead of trying to limp it home about 5-6 mile I decided it was best to just call a tow truck and ruin the engine.

When the tow truck driver arrived he put the transfer case in neutral along with the transmission. He then winched up on the roll-back and secured it.When he dropped me off he rolled the truck off the back and then put the tranfer case back in 4-HI LOC. Ever since this the truck is a free roller in Park. It drives fine forward and reverse - it doesn't matter what range the transfer case is in either.

[Blue_71]

hmm, that is defintly odd. my best suggestion, would be to unhook the linkage from the side of the trans, then make sure it is fully in park by trying to move the mechanism on the side of the trans. after making sure it is fully in park, try rolling the truck to see if it will move. id be sure to have the wheels blocked while your up under it, in case you accidently turn the mechanism the wrong way.

im thinking maybe somewhere in the belt slinging/balancer throwing that a linkage may have gotten bent.. other than that, i have no idea

[ch2000]

Thanks for the insight, I will look into that this weekend.